Friction clutch plate



.Fan.5, 1943. w. v. THELANDER 2,307,340

FRICTION CLUTCH PLATE Original Filed July 22, 1959 Patented Jan. 5, 1943W. Vincent Thelander, Auburn, Ind.

Original application July 22, 1939, Serial No.

285,840. Divided and this application December 22, 1941, Serial No.424,083

Claims.

This application is a division of my copending application Serial No.285,840, filed July 22, 1939.

This invention relates to improvements in friction clutches for. motorvehicles and is particularly concerned with a new and improved clutchplate.

Clutch plates have been spring cushioned to dampen vibrations, and alongwith the spring cushioning means many have seen fit to providefrictional means of one kind or another to resist relative movementbetween the plate and its hub, the theory being that the larger andharsher power impulses are absorbed by the spring cushioning meanswhereas the minor engine vibrations, which when synchronized with thevibrations from the rear portion of the transmission train set up a highfrequency noise, are absorbed or, dampened by the separate brakingmeans. However, realizing that to be mere theory which moreover meantthe addition of complicated and expensive construction, which if itcould be eliminated or at least simplified would make possible themanufacture of clutch plates at much lower cost, I experimented andgradually reduced the friction lag or drag and found that there was lessand less vibration and noise noticeable in the car. I have, therefore,come to the conclusion that the more accurate theory is this:

The springs for cushioning purposes are in and of themselves a vibrationdampening means in addition to transmitting power, and it is thereforeto no purpose to tie together by friction means the relatively rotatableplate and hub but the addition of such friction means serves only toconduct to an undesired degree vibrations from the rear portion of thetransmission train to the plate, which then acts as a sounding board ordiaphragm amplifying the audible noises. It is therefore the principalobject of my invention to provide a spring cushioned clutch plate devoidof frictional braking means and in fact specially constructed with aview to obtaining as nearly as possible zero friction lag or dragbetween the plate and its hub. It is also an important object to havethe plate of sectional construction so as to reduce whatever smallamount of sounding board or diaphragm effect might otherwise still benoticeable.

The invention is illustrated in the accompanying drawing, in which-Figure 1 is a face view of a clutch plate made in accordance with myinvention showing two of the spring pockets in outside elevation, athird in longitudinal section, and a fourth broken away The samereference numerals are applied to corresponding parts in these views.

The clutch plate shown at 5 is generally similar to that disclosed in myPatent 2,244,134, and comprises relatively rotatable inner and outerportions, the inner portion being formed by a center hub 6 splined fordriving connection with the driving shaft of the transmission andprovided with an annular flange I onto which the outer portion 8 of'theplate is adapted to be assembled in true concentric relation with thecircular periphery 9 of the flange. The outer portion 8 in accordancewith my patent is made up of an even number of section l0, eight beingshown in the present case, four facing one way and the other four facingthe other way. With that number of sections I provide four springpockets II for cooperation with registering substantially rectangularopenings l2 in the flange I; because each section It! has an ear I3overlying one side of the flange 1 andformed to provide therein astruck-out or embossed portion ll of substantially semicylindrical formto form half of a spring pocket. The pockets ll form housings for thespring cushioning means consisting of a set of heavy coiled compressionsprings l5, one in each pocket, fitting in the openings l2 and housedbetween the embossed portions l4 of the ears l3. Assuming the drive tobe in the direction of the arrow at in Figure 1, that is clockwise, thedrive is assumed by the springs l5 bearing against one end wall l6 ofeach of the pockets ll while the other ends of the springs bear againstthe opposite end I! of the openings I2 in the flange I. In coasting,when the drive is from the hub 6 to the outer section 8 through theflange I, the springs l5 act between the other ends l8 of the openingsl2 and the opposite end walls 19 of the pockets H, By assembling thesprings IS in rectangular openings I! as distinguished from notchesopening to the periphery of the flange l, I avoid danger of the springsmoving outwardly under centrifugal force when the clutch plate turns athigh speed, there being the connecting web portions 20 at the peripheryof flange I to retain the springs IS in normal position. The flange l isfurthermore strengthened by these web portions 20 so that there is lesslikelihood of distortion of the flange under long service.

The mode of assembling the multi-section plate using the eight stampedsheet metal plate sections III is more fully disclosed in my patentabove mentioned, but a study of Figure 1 should serve to make theconstruction clear. Looking at that plate section III which has thespring pocket and spring therein appearing in section, it will be seenthat the ear is from which the semi-cylindrical pocket part II is struckextends approximately half the length of the arcuate bow 2| of the platesection and is disposed between two rivet holes 22 and 23 on that halfof the body, a third rivet hole 24 being provided in the other end ofthe body. The ear II projects radially inwardly from the inner arcuateedge 25 of the body and there is a segmental-shaped larger ear 28projecting radially from the outer arcuateedge 21 of the body at themiddle thereof, the ear 28 being symmetrical with respect to the middlerivet holes 23, as shown. The ears "on the correlated plate sections inthe assembled plate I provide an annulaar mat support for application ofthe facings 28 of suitable composition material, usually containingasbestos. The main body portion 2| of each plate section is in one planeexcept for the small end portion 29 struck out of the plane of the bodyportion an amount equivalent to the thickness of a plate section so thatwhen two plate sections are placed face to face there is enough spaceleft therebetween for the free end portion 30 of a third plate section.In fact, each of the rivets 3| for fastening the plate sections togetherpasses through registering holes in three overlapping sections. Thusplate sections on the one face of the plate are overlapped at adjoiningends so that the rivet hole 22 in one section registers with the rivethole 24 in the next section and so on. The same is true on the otherface of theplate 5 but the plate sections on that face are reversed endfor end and offset angularly enough tobring the ears l3 on the two facesof the plate in register to form the'pockets II. In that way the rivetholes 22 and 24 of one set of plate sections register with theintermediate rivet holes 23 in the other set. In passing it will also beobserved that the ears 13 are struck out of' the plane of the main bodyportion 2| approximately in the-same plane with the opposite endportions 29. Thus when the plate sections are assembled together in themanner described, all of the ears i3 of one set are in one planeparallel with the plane of one face of the flange 1 whereas the ears l3of the other set are in a parallel plane parallel with the plane of theother face of the flange I. The interchangeability of the plate sectionsmakes for quick and easy assembling of these clutch plates, and also isan important factor in reducing cost because of the saving in die coststhereby.

realized. The fact that each plate section represents approximatelyone-eighth of a whole plate means that the individual section can beproduced from such a small piece of sheet metal that scrap from theproduction of other sheet metal articles may be used and a great savingin cost thereby efiected.. The small size and the particular shape ofthe individual plate sections also permits stamping the same fromregular sheet stock with very little waste-much less than is necessarilyinvolved where a whole plate is punched out-and there is accordingly anappreciable saving in cost even where ordinary methods of production arefollowed.

The plate sections of both sets have an easy 75workingfltonthecirculsrperlpherylofthe flange .I of the huh I byengagement of the orouate inner peripheries 2| thereon, deflnite wideclearances being left otherwise between the outer section I of the plateI and the circular periphcry I of the flange 1 as indicated clearly inthe two views. Notice the wide clearance at I2 between the outerperiphery I of the flange I and the arcuate outer wall of the pockets l4and also the wide clearances at II between the inner sides of the earsII and both sides of the flange I. The

Y outer section I of the plate I is therefore in floating relation tothe flange 1 of the hub I with a view to obtaining zero friction lag ordrag, as nearly as that is possible in commercial production of frictionclutch plates in large quantities. To illustrate to what a marked degreethe friction drag has been reduced, I might state that whereas thestandard practice among clutch manufacturers is to provide frictionbraking means effective to the extent of providing from one and one-halfto three foot pounds of friction drag, I have eliminated the brakingmeans and otherwise specially constructed the plate so as to reduce thefriction drag to approximately a half foot pound. Extensive tests haveshown that the more the friction drag was reduced the less the vibrationand noise otherwise noticeable in the car became. The vibration wasmeasured with a diaphragm or amplifier on the gear shift lever andbecame less and less perceptible with the reduction in friction drag. Iam therefore convinced that the springs II constitute a vibrationdampening means hesides serving as a resilient power transmitting meansand that any frictional braking means between the ,plate and its hub isabsolutely non-essential and, far from serving a useful p pose, isactually detrimental because of the conduction therethrough ofvibrations from the hub to the plate. with my construction thetransmission of vibration from the hub to the plate is minimized bykeeping the plate in floating relation to the hub axially and havingonly sufficient bearing engagement peripherally of the hub to keep the rplate in centered relation therewith. The axial float is provided by theclearances II as previously indicated, and the plate has bearingengagement with its inner periphery 2! on the outer periphery I of theflange I to keep the plate in centered relation to the hub I. Thesectional construction of the plate is further believed to beresponsible for reduction in noise because it is obvious that a built-upplate does not have the same sound amplification properties as aone-piece plate.

The ears 28 are struck out of the plane of the main body portions 21 toa slight extent, as indicated in Fig. 2, and since the ears 2I of oneset of plate sections are offset in one direction with respect to theplane of the plate and the ears 28 of. the other set are offset in theopposite direction, as clearly appears in Fig. 2, the space left betweenthe ears of the two sets, indicated at 34. results in a desired musheffect. Rivets entered through the ends of the mats 28 serve to secureone mat to each of the ears 26, and another rivet II entered through themiddle of each mat serves to prevent buckling thereof away from thesupporting ear.

It is believed the foregoing description conveys a good understanding ofthe objects and advantages of my invention. The appended claims havebeen drawn to cover all legitimate modifications and adaptations.

I claim:

1. A spring cushioned vibration dampening clutch plate comprising acenter hub having an annular flange with a circular periphery concentriowith the hub, a friction material supporting annulus having the outermarginal portion thereof carrying the friction material and having theinner marginal portion thereof disposed in overlapping relation withboth side faces of the flange and fitting loosely around the hub, saidannulus having an annular shoulder thereon radially between the outerand inner marginal portions slidably engaging the periphery of saidflange, said flange having one or more openings provided therein forspring cushioning means, and spring cushioning means in said openingsfor transmitting drive resiliently between the annulus and hub.

2. A spring cushioned vibration dampening clutch plate comprising acenter hub having an annular flange with a circular periphery concentricwith the hub, a plurality of clutch plate sections circumferentiallyarranged around the hub, some of the sections overlapping the front faceof the flange and some of said sections overlapping the rear facethereof, whereby to limit axial displacement of the hub with respect tosaid plate sections, means for fastening said plate sections togetherforming an annulus substantially concentric with the hub, said annulusdeflning an annular shoulder thereon radially between theouter and innermarginal portions thereof concentric with the annulus and slidablyengaging the periphery of said flange, said flange having one or moreopenings provided therein for spring cushioning means, spring cushioningmeans in said openings for transmitting drive resiliently between theannulus and hub.

3. A spring cushioned vibration dampening clutch plate, comprising acenter hub having an annular flange with a circular periphery concentricwith the hub, a plurality of clutch plate sections circumferentiallyarranged around the hub, some of the sections overlapping the front faceof the flange and some of said sections overlapping the rear facethereof, whereby to limit axial displacement of the hub with respect tosaid plate sections, means for fastening said plate sections togetherforming an annulus substantially concentric with the hub, said annulusdeflning an annular shoulder thereon radially between the outer andinner marginal portions thereof concentric with the annulus and slidablyengaging the periphery of said flange, the inner marginal portions ofsaid plate sections overlapping the flange being formed to providepockets, and said flange being formed to provide circumferentiallyspaced cut-out portions in register with said' pockets defining drivefaces at opposite ends thereof in circumferentially spaced relation, theopposite ends of the pockets also defining driving faces, and springmeans enclosed in said pockets for engagement at one end with a driveface on the flange and at the other end with a drive face in thepockets, said spring means being adapted to be assembled in the pocketsand cut-out portions prior to the fastening together of the platesections.

4. A spring cushioned vibration dampening clutch plate, comprising acenter hub having an annular flange with a. circular periphery concentric with the hub, a plurality of clutch plate sectionscircumferentially arranged around the hub, some of the sectionsoverlapping the front face. of the flange and some of said sectionsoverlapping the rear face thereof, whereby to limit axial displacementof the hub with respect to said plate sections, means for fastening saidplate sections together forming an annulus substantially concentric withthe hub, said annulus defining an annular shoulder thereon radiallybetween the outer and inner marginal portions thereof concentric withthe annulus and slidably engaging the periphery of said flange, saidflange having one or more openings provided therein for springcushioning means, spring cushioning means in said openings fortransmitting drive resiliently between the annulus and hub, andannularly arranged pieces of friction material supported on oppositesides of the annulus in substantially concentric relation with the hub,the pieces being secured individually to the outer marginal portions ofthe plate sections, the outer marginal portions of some of said platesections being normally disposed in a plane in spaced substantiallyparallel relation to the outer marginal portions of the other platesections.

5. A spring cushioned clutch plate, comprising a center hub having anannular flange with a circular'periphery concentric with the hub, aclutch plate structure carried thereby and movable rotatively relativethereto against spring resistance, comprising a plurality of platesections circumferentially arranged around the flange, some having theirradially inner portions overlapping one side of the flange and othershaving their radially inner portions overlapping the opposite side ofthe flange, whereby to limit axial displacement of the clutch platestructure relative to the hub in either direction, means for securingthe plate sections together forming an annulus substantially concentricwith the hub and slidably engaging the periphery of said'flange tomaintain concentric relationship with the hub in its movement rotativelyrelative thereto, and spring cushioning means for resilientlytransmitting drive between the hub and clutch plate structure, saidflange radially inwardly from its peripheral engagement with the platesections being of reduced thickness so that its opposite side faces arespaced from the plate sections to minimize the transmission of vibrationfrom the hub to said plate sections, and said clutch plate structurecarrying friction material thereon for drive purposes, the built-upsectional construction of said plate structure resulting in minimumsound so amplification incident to whatever vibrations are transmittedthereto from the hub.

w. vmcnm' Tmannna.

